Cellular damage mechanism induced by photo-excited titanium dioxide nanoparticles used in sunscreens

VAUDAGNA, V.; ZOPPI, A.; AIASSA, V.; BECERRA, M.C.; SILVERO, M. J.

Virtual

Congreso; V Reunión Grupo Argentino de Fotobiología; 2020

CELLULAR DAMAGE MECHANISM INDUCED BY PHOTO-EXCITED TITANIUMDIOXIDE NANOPARTICLES USED IN SUNSCREENSVaudagna, M. Virginia 2; Zoppi, Ariana 1; Aiassa, Virginia 1; Becerra, M. Cecilia 2; Silvero C, M. Jazmin2.LINBIO (Laboratorio de Investigación en NanoBiotecnología) - Dpto. Cs. Farmacéuticas, Facultad de Cs Químicas, Univ.Nacional de Córdoba, Córdoba X5000, Argentina . 1:UNITEFA (CONICET); 2:IMBIV (CONICET).Presentador/a: Silvero Email: jazmincompagnucci@gmail.comTITANIUM DIOXIDE (TIO2) IS WIDELY USED IN SUNSCREENS BECAUSE IT PROTECTS AGAINST UV RADIATION.CURRENT ONES ARE MICRONIZED OR NANOPARTICLE FORMULATIONS (TIO2@NP), WHICH BLEND WITHTHE SKIN TONE AND ATTAIN A BETTER COSMETIC EFFECT. NANOSIZED TITANIUM DIOXIDE IS APPROVED BYTHE FOOD AND DRUG ADMINISTRATION, BUT ITS BIOCOMPATIBILITY IS CONTROVERSIAL. CONCERN ABOUTNEGATIVE EFFECTS HAS LATELY BEEN RAISED. IN FACT, CYTOTOXICITY AND OXIDATIVE STRESS PRODUCEDBY TIO2@NP WHEN EXPOSED TO SUNLIGHT WERE DEMONSTRATED IN SOME STUDIES. THE GOAL OF THISWORK WAS TO PROPOSE AN ALTERNATIVE TO THE CELLULAR DAMAGE GENERATED UPON THEINTERACTION OF TIO2@NP WITH SUNLIGHT.ANTIOXIDANT VITAMINS B2 (RIBOFLAVIN) AND VITAMIN CWERE TRIED AS FUNCTIONALIZATION AGENTS BECAUSE THEIR POTENTIAL TO BIND TO THE NANOPARTICLEAND THE CAPACITY OF NEUTRALIZE THE OXIDATIVE STRESS. BINDING WAS ACHIEVED AFTER A FEWMINUTES OF SONICATION IN AQUEOUS MEDIA, FOLLOWED BY CHARACTERIZATION. WE USED A MODEL OFPROKARYOTIC CELLS (METHICILLIN-SENSITIVE STAPHYLOCOCCUS AUREUS BIOFILM) EXPOSED TO LIGHT TOSTUDY THE PROTECTIVE CAPACITY OF VITAMINS@TIO2NP. VIABILITY WAS ASSESSED USING THE XTT ASSAY.THE ABSORBANCE VALUES ARE PROPORTIONAL TO THE METABOLIC ACTIVITY OF THE CELLS AND INDICATECELL SURVIVAL. THE TIO2@NP FUNCTIONALIZED WITH VITAMIN B2 WERE THE MORE STABLE ONES, ANDWERE CHOSEN TO FOLLOW THE EXPERIMENTS. THE ANALYSIS OF THE SUPERNATANT BY UV-VISSPECTROMETRY SHOWED THAT EVERY GRAM OF TIO2@NP IS LOADED WITH 0.8 GRAMS OF VITAMIN B2.THE IR SPECTRUM OF VITAMINB2@TIO2NP SHOWED SIGNS OF BINDING BETWEEN COMPOUNDS. THE OHBENDING PEAK (1634 CM-1) CORRESPONDING TO BARE NANOPARTICLE DISAPPEARED AND THE NH2BENDING BAND CHARACTERISTIC OF VITAMIN B2 APPEARED (1650 CM-1). IN SAMPLES TREATED WITHVITAMINB2@TIO2NP IRRADIATED FOR UP TO 6 H, THE LEVELS OF REACTIVE OXYGEN SPECIES (NBT ASSAY)AND PROTEIN OXIDATION (AOPP ASSAY) WERE COMPLETELY DECREASED. THE LIPID OXIDATION (MDAASSAY) WAS ALSO REMARKABLY LOWER WHEN USING VITAMINB2@TIO2NP (64 % LESS). THE BARE OXIDENPS ARE HARMFUL, IN PART, BECAUSE BOTH ANATASE AND RUTILE FORMS ARE SEMICONDUCTORS ANDPRODUCE HIGH AMOUNTS OF ROS UPON SUNLIGHT. MOREOVER, THE CELL VIABILITY PERCENT FORPROKARYOTIC CELLS IMPROVED WHEN THEY WERE TREATED WITH VITAMINB2@TIO2NP (153 ± 9%)COMPARED TO THE ONES TREATED WITH BARE TIO2@NP (82 ± 3%).FUNCTIONALIZATION WITH VITAMINB2 PROVED TO BE A BIOCOMPATIBLE AND LOW-COST ALTERNATIVE TO PROTECT THE CELLS FROM THISOXIDATIVE STRESS. THEREFORE, WE PLAN TO CONTINUE THIS STUDY ON EUKARYOTIC CELLS AND IN VIVO,TO CHECK THE PENETRATION AND BIODISTRIBUTION OF THE NANOPARTICLES.Bibliografía: Andreoli, C., Leter, G., Berardis, B.D., Degan, P., Angelis, I.D., Pacchierotti, F., Crebelli, R., et al.2018. Critical issues in genotoxicity assessment of TiO2 nanoparticles by human peripheral bloodmononuclear cells. Journal of Applied Toxicology, 38 (12), 1471-1482.Área temática: MECANISMOS MOLECULARES DE PROCESOS FOTOINDUCIDOS